Cam phaser for engines having two check valves in rotor between chambers and spool valve
US6763791B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2002 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Jul 18, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01L2001/34426
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An infinitely variable camshaft timing device (phaser) has a control valve located in the rotor. Since the control valve is in the rotor, the camshaft need only provide a single passage for supplying engine oil or hydraulic fluid, and does not need multiple passageways for controlling the phaser, as in the prior art. Two check valves, an advance chamber check valve and a retard chamber check valve, are also located in the rotor. The check valves are located in the control passages for each chamber. The main advantage of putting the check valves in the advance and retard chambers instead of having a single check valve in the supply is to reduce leakage. This design also eliminates high pressure oil flow across the spool valve and improves the response time of the check valve to the torque reversals due to a shorter oil path. In addition, the phaser of the present invention outperforms an oil pressure actuated device and consumes less oil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.